SPFI conversion problem: No Spark!

[subynut]

I just finished converting my carbed 86 wagon to SPFI out of an 88 by following the guide in the USRM.

However, I have no spark. I tried swapping the ditsy with a spare; no change. I would test the ditsy in my brothers' Suby, but the connectors are differant between 87 and 88. I tested the coil/transistor assembly and that tested good. I tested for power at the connectors of the ditsy and the power transistor and I have power there. I checked for codes and all I get is 34 and 35: EGR sol. valve and Purge control valve. What else could it be?

I have an oscilliscope, so if I need to check for waveforms I can. I would just need some idea as to what the waveforms are supposed to look like. Help?!?!?!?

[calebz]

You can swap the wiring pigtails between 87 and 88. takes about 5 minutes and requires a phillips screwdriver.. That may help in your testing.

[subynut]

Oh, ok, I'll give that a try.

[subynut]

Well, I took the ditsy apart, but the wires are molded into the sensor. I was hoping I could just swap the pigtails, but that won't be possible. I was going to test the ditsy in my brother's car, but unless I cut and solder, then cut and resolder the wires, I don't think I can swap the ditsys just for a test.

Do you know if the ECUs are the same? One's a 87 used to be AT now MT. And the other is a 88 MT. Just trying to pinpoint the problem. Any other ideas as to why there's no spark?

[MorganM]

Coil hooked up properly? Easy to swap those wires.

 

Ignitor assembly bracket properly grounded? That will cause a no-go right there. Check all grounds

[subynut]

It's mounted in the spare tire area using one of the bolts that holds the A/C hose in place. I also have that ground wire that is amidst that bundle of wires attatched to the chassis also.

[MorganM]

make sure coil is hooked up properly:

 

black/white from ECU to ignitor

yellow from ECU to ignitor

 

black/white from ECU to + on coil

yellow from ECU to - on coil

 

black/white from ingitor to + on coil

blue from ignitor to - on coil

 

So you should have two black/white wires on + at coil

Yellow and blue on - at coil

[subynut]

Ok, the wires to the coil are correct. But I'll hafta check the ignitor connector when I get home from work. I know there is a black/white wire at the ignitor connector, don't remember what the other wire color is. When I pulled the wiring harness out of the parts car, I kept everything in tact(no cutting any wires) and I made sure that the wiring looked good (no fraying or broken insulation) before I installed it into the car.

What happends during the start procedure? Detects the start signal from the starter, checks if the neutral safety switch is on, what else? The starter wire is hooked up and the neutral safty switch is disconnected.

[subynut]

It runs! You were right. The ignitor wasn't properly grounded. Ran a wire from the ignitor base to a ground point on the engine and VROOM! WOO HOO!! Now, all I need is a Purge control valve and a EGR sol valve. I know, they're not really necissary for engine performance, but I would prefer them to be there.

I took her out for a test drive and there is a little hesitation thruout the rpm range. Just slight glitches I can feel. I havn't installed the y-pipe with the o2 sensor yet, funny how the ECU isn't complaining about it. Very odd, but anyways, I don't know if that has anything to do with it.

Thanks MorganM!

[MorganM]

Awsome! Glad it's up and running. Funny how one little ground just ruins the day.